Elodea canadensis

Elodea canadensis (American waterweed or Canadian waterweed or pondweed) is a perennial aquatic plant, or submergent macrophyte, native to most of North America. It has been introduced widely to regions outside its native range and was first recorded from the British Isles in about 1836. The native range of the species lies within North America, but it has been introduced in many parts of the world either intentionally or not. Europe has been particularly affected with the first record dating back as far as 1836. Since then, the species’ presence has been confirmed in all continental European countries. Records of the species' presence in Ireland include: County Galway, found at several sites along the Eglinton Canal, County Galway,County Down. and from the Lagan Canal near Lisburn, Northern Ireland.